Technical Field
The present invention relates to a technique of issuing a warning depending on temperature of a friction element.
Related Art
When temperature of a friction element that is used for a power train, such as a clutch, a brake, or the like, becomes high, seizure or burnout is caused. In JP2008-57670A, therefore, heating quantity of the friction element is calculated based on a rotation speed difference of the friction element and input torque to the friction element and, based on the calculated heating quantity, the temperature of the friction element is estimated. When the estimated temperature of the friction element exceeds upper limit temperature, a warning lamp is turned on.